8.9

1 files changed, 75 insertions, 240 deletions

diff --git a/zen/symlink_target.h b/zen/symlink_target.h
index e3f526ba..4620e7cc 100644..100755
--- a/zen/symlink_target.h
+++ b/zen/symlink_target.h
@@ -1,240 +1,75 @@
-// *****************************************************************************
-// * This file is part of the FreeFileSync project. It is distributed under    *
-// * GNU General Public License: http://www.gnu.org/licenses/gpl-3.0           *
-// * Copyright (C) Zenju (zenju AT freefilesync DOT org) - All Rights Reserved *
-// *****************************************************************************
-
-#ifndef SYMLINK_TARGET_H_801783470198357483
-#define SYMLINK_TARGET_H_801783470198357483
-
-#include "scope_guard.h"
-#include "file_error.h"
-
-#ifdef ZEN_WIN
-    #include "win.h" //includes "windows.h"
-    #include "privilege.h"
-    #include "long_path_prefix.h"
-    #include "dll.h"
-
-#elif defined ZEN_LINUX || defined ZEN_MAC
-    #include <unistd.h>
-    #include <stdlib.h> //realpath
-#endif
-
-
-namespace zen
-{
-#ifdef ZEN_WIN
-    bool isSymlink(const WIN32_FIND_DATA& data); //checking FILE_ATTRIBUTE_REPARSE_POINT is insufficient!
-    bool isSymlink(DWORD fileAttributes, DWORD reparseTag);
-#endif
-
-Zstring getResolvedSymlinkPath(const Zstring& linkPath); //throw FileError; Win: requires Vista or later!
-Zstring getSymlinkTargetRaw   (const Zstring& linkPath); //throw FileError
-}
-
-
-
-
-
-
-
-
-
-//################################ implementation ################################
-#ifdef ZEN_WIN
-//I don't have Windows Driver Kit at hands right now, so unfortunately we need to redefine this structure and cross fingers...
-typedef struct _REPARSE_DATA_BUFFER //from ntifs.h
-{
-    ULONG  ReparseTag;
-    USHORT ReparseDataLength;
-    USHORT Reserved;
-    union
-    {
-        struct
-        {
-            USHORT SubstituteNameOffset;
-            USHORT SubstituteNameLength;
-            USHORT PrintNameOffset;
-            USHORT PrintNameLength;
-            ULONG  Flags;
-            WCHAR  PathBuffer[1];
-        } SymbolicLinkReparseBuffer;
-        struct
-        {
-            USHORT SubstituteNameOffset;
-            USHORT SubstituteNameLength;
-            USHORT PrintNameOffset;
-            USHORT PrintNameLength;
-            WCHAR  PathBuffer[1];
-        } MountPointReparseBuffer;
-        struct
-        {
-            UCHAR DataBuffer[1];
-        } GenericReparseBuffer;
-    };
-} REPARSE_DATA_BUFFER, *PREPARSE_DATA_BUFFER;
-#define REPARSE_DATA_BUFFER_HEADER_SIZE   FIELD_OFFSET(REPARSE_DATA_BUFFER, GenericReparseBuffer)
-#endif
-
-namespace
-{
-//retrieve raw target data of symlink or junction
-Zstring getSymlinkRawTargetString_impl(const Zstring& linkPath) //throw FileError
-{
-    using namespace zen;
-#ifdef ZEN_WIN
-    //FSCTL_GET_REPARSE_POINT: https://msdn.microsoft.com/en-us/library/aa364571
-
-    //reading certain symlinks/junctions requires admin rights!
-    try
-    { activatePrivilege(PrivilegeName::BACKUP); } //throw FileError
-    catch (FileError&) {} //This shall not cause an error in user mode!
-
-    const HANDLE hLink = ::CreateFile(applyLongPathPrefix(linkPath).c_str(), //_In_      LPCTSTR lpFileName,
-                                      //it seems we do not even need GENERIC_READ!
-                                      0,                 //_In_      DWORD dwDesiredAccess,
-                                      FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE,    //_In_      DWORD dwShareMode,
-                                      nullptr,           //_In_opt_  LPSECURITY_ATTRIBUTES lpSecurityAttributes,
-                                      OPEN_EXISTING,     //_In_      DWORD dwCreationDisposition,
-                                      FILE_FLAG_BACKUP_SEMANTICS | FILE_FLAG_OPEN_REPARSE_POINT, //_In_      DWORD dwFlagsAndAttributes,
-                                      nullptr);          //_In_opt_  HANDLE hTemplateFile
-    if (hLink == INVALID_HANDLE_VALUE)
-        THROW_LAST_FILE_ERROR(replaceCpy(_("Cannot resolve symbolic link %x."), L"%x", fmtPath(linkPath)), L"CreateFile");
-    ZEN_ON_SCOPE_EXIT(::CloseHandle(hLink));
-
-    //respect alignment issues...
-    const DWORD bufferSize = REPARSE_DATA_BUFFER_HEADER_SIZE + MAXIMUM_REPARSE_DATA_BUFFER_SIZE;
-    std::vector<char> buffer(bufferSize);
-
-    DWORD bytesReturned = 0; //dummy value required by FSCTL_GET_REPARSE_POINT!
-    if (!::DeviceIoControl(hLink,                   //__in         HANDLE hDevice,
-                           FSCTL_GET_REPARSE_POINT, //__in         DWORD dwIoControlCode,
-                           nullptr,                 //__in_opt     LPVOID lpInBuffer,
-                           0,                       //__in         DWORD nInBufferSize,
-                           &buffer[0],              //__out_opt    LPVOID lpOutBuffer,
-                           bufferSize,              //__in         DWORD nOutBufferSize,
-                           &bytesReturned,          //__out_opt    LPDWORD lpBytesReturned,
-                           nullptr))                //__inout_opt  LPOVERLAPPED lpOverlapped
-        THROW_LAST_FILE_ERROR(replaceCpy(_("Cannot resolve symbolic link %x."), L"%x", fmtPath(linkPath)), L"DeviceIoControl, FSCTL_GET_REPARSE_POINT");
-
-    REPARSE_DATA_BUFFER& reparseData = *reinterpret_cast<REPARSE_DATA_BUFFER*>(&buffer[0]); //REPARSE_DATA_BUFFER needs to be artificially enlarged!
-
-    Zstring output;
-    if (reparseData.ReparseTag == IO_REPARSE_TAG_SYMLINK)
-    {
-        output = Zstring(reparseData.SymbolicLinkReparseBuffer.PathBuffer + reparseData.SymbolicLinkReparseBuffer.SubstituteNameOffset / sizeof(WCHAR),
-                         reparseData.SymbolicLinkReparseBuffer.SubstituteNameLength / sizeof(WCHAR));
-    }
-    else if (reparseData.ReparseTag == IO_REPARSE_TAG_MOUNT_POINT)
-    {
-        output = Zstring(reparseData.MountPointReparseBuffer.PathBuffer + reparseData.MountPointReparseBuffer.SubstituteNameOffset / sizeof(WCHAR),
-                         reparseData.MountPointReparseBuffer.SubstituteNameLength / sizeof(WCHAR));
-    }
-    else
-        throw FileError(replaceCpy(_("Cannot resolve symbolic link %x."), L"%x", fmtPath(linkPath)), L"Not a symbolic link or junction.");
-
-    //absolute symlinks and junctions use NT namespace naming convention while relative ones do not:
-    //https://msdn.microsoft.com/en-us/library/windows/desktop/aa365247#NT_Namespaces
-    return ntPathToWin32Path(output);
-
-#elif defined ZEN_LINUX || defined ZEN_MAC
-    const size_t BUFFER_SIZE = 10000;
-    std::vector<char> buffer(BUFFER_SIZE);
-
-    const ssize_t bytesWritten = ::readlink(linkPath.c_str(), &buffer[0], BUFFER_SIZE);
-    if (bytesWritten < 0)
-        THROW_LAST_FILE_ERROR(replaceCpy(_("Cannot resolve symbolic link %x."), L"%x", fmtPath(linkPath)), L"readlink");
-    if (bytesWritten >= static_cast<ssize_t>(BUFFER_SIZE)) //detect truncation, not an error for readlink!
-        throw FileError(replaceCpy(_("Cannot resolve symbolic link %x."), L"%x", fmtPath(linkPath)), L"readlink: buffer truncated.");
-
-    return Zstring(&buffer[0], bytesWritten); //readlink does not append 0-termination!
-#endif
-}
-
-
-Zstring getResolvedSymlinkPath_impl(const Zstring& linkPath) //throw FileError
-{
-    using namespace zen;
-#ifdef ZEN_WIN
-    //GetFinalPathNameByHandle() is not available before Vista!
-    using GetFinalPathNameByHandleWFunc = DWORD (WINAPI*)(HANDLE hFile, LPTSTR lpszFilePath, DWORD cchFilePath, DWORD dwFlags);
-    const SysDllFun<GetFinalPathNameByHandleWFunc> getFinalPathNameByHandle(L"kernel32.dll", "GetFinalPathNameByHandleW");
-    if (!getFinalPathNameByHandle)
-        throw FileError(replaceCpy(_("Cannot determine final path for %x."), L"%x", fmtPath(linkPath)), replaceCpy(_("Cannot find system function %x."), L"%x", L"\"GetFinalPathNameByHandleW\""));
-
-    const HANDLE hFile = ::CreateFile(applyLongPathPrefix(linkPath).c_str(),                  //_In_      LPCTSTR lpFileName,
-                                      0,                                                      //_In_      DWORD dwDesiredAccess,
-                                      FILE_SHARE_READ | FILE_SHARE_WRITE | FILE_SHARE_DELETE, //_In_      DWORD dwShareMode,
-                                      nullptr,                    //_In_opt_  LPSECURITY_ATTRIBUTES lpSecurityAttributes,
-                                      OPEN_EXISTING,              //_In_      DWORD dwCreationDisposition,
-                                      //needed to open a directory:
-                                      FILE_FLAG_BACKUP_SEMANTICS, //_In_      DWORD dwFlagsAndAttributes,
-                                      nullptr);                   //_In_opt_  HANDLE hTemplateFile
-    if (hFile == INVALID_HANDLE_VALUE)
-        THROW_LAST_FILE_ERROR(replaceCpy(_("Cannot determine final path for %x."), L"%x", fmtPath(linkPath)), L"CreateFile");
-    ZEN_ON_SCOPE_EXIT(::CloseHandle(hFile));
-
-    const DWORD bufferSize = getFinalPathNameByHandle(hFile, nullptr, 0, 0);
-    if (bufferSize == 0)
-        THROW_LAST_FILE_ERROR(replaceCpy(_("Cannot determine final path for %x."), L"%x", fmtPath(linkPath)), L"GetFinalPathNameByHandle");
-
-    std::vector<wchar_t> targetPath(bufferSize);
-    const DWORD charsWritten = getFinalPathNameByHandle(hFile,          //__in   HANDLE hFile,
-                                                        &targetPath[0], //__out  LPTSTR lpszFilePath,
-                                                        bufferSize,     //__in   DWORD cchFilePath,
-                                                        0);             //__in   DWORD dwFlags
-    if (charsWritten == 0)
-        THROW_LAST_FILE_ERROR(replaceCpy(_("Cannot determine final path for %x."), L"%x", fmtPath(linkPath)), L"GetFinalPathNameByHandle");
-    if (charsWritten >= bufferSize)
-        throw FileError(replaceCpy(_("Cannot determine final path for %x."), L"%x", fmtPath(linkPath)), L"GetFinalPathNameByHandle: insufficient buffer size.");
-
-    return removeLongPathPrefix(Zstring(&targetPath[0], charsWritten)); //MSDN: GetFinalPathNameByHandle() always prepends "\\?\"
-
-#elif defined ZEN_LINUX || defined ZEN_MAC
-    char* targetPath = ::realpath(linkPath.c_str(), nullptr);
-    if (!targetPath)
-        THROW_LAST_FILE_ERROR(replaceCpy(_("Cannot determine final path for %x."), L"%x", fmtPath(linkPath)), L"realpath");
-    ZEN_ON_SCOPE_EXIT(::free(targetPath));
-    return targetPath;
-#endif
-}
-}
-
-
-namespace zen
-{
-inline
-Zstring getSymlinkTargetRaw(const Zstring& linkPath) { return getSymlinkRawTargetString_impl(linkPath); }
-
-inline
-Zstring getResolvedSymlinkPath(const Zstring& linkPath) { return getResolvedSymlinkPath_impl(linkPath); }
-
-#ifdef ZEN_WIN
-/*
- Reparse Point Tags
-    https://msdn.microsoft.com/en-us/library/windows/desktop/aa365511
- WIN32_FIND_DATA structure
-    https://msdn.microsoft.com/en-us/library/windows/desktop/aa365740
-
- The only surrogate reparse points are;
-    IO_REPARSE_TAG_MOUNT_POINT
-    IO_REPARSE_TAG_SYMLINK
-*/
-
-inline
-bool isSymlink(DWORD fileAttributes, DWORD reparseTag)
-{
-    return (fileAttributes & FILE_ATTRIBUTE_REPARSE_POINT) != 0 &&
-           IsReparseTagNameSurrogate(reparseTag);
-}
-
-inline
-bool isSymlink(const WIN32_FIND_DATA& data)
-{
-    return isSymlink(data.dwFileAttributes, data.dwReserved0);
-}
-#endif
-}
-
-#endif //SYMLINK_TARGET_H_801783470198357483
+// *****************************************************************************

+// * This file is part of the FreeFileSync project. It is distributed under    *

+// * GNU General Public License: http://www.gnu.org/licenses/gpl-3.0           *

+// * Copyright (C) Zenju (zenju AT freefilesync DOT org) - All Rights Reserved *

+// *****************************************************************************

+

+#ifndef SYMLINK_TARGET_H_801783470198357483

+#define SYMLINK_TARGET_H_801783470198357483

+

+#include "scope_guard.h"

+#include "file_error.h"

+

+    #include <unistd.h>

+    #include <stdlib.h> //realpath

+

+

+namespace zen

+{

+

+Zstring getResolvedSymlinkPath(const Zstring& linkPath); //throw FileError; Win: requires Vista or later!

+Zstring getSymlinkTargetRaw   (const Zstring& linkPath); //throw FileError

+}

+

+

+

+

+

+

+

+

+

+//################################ implementation ################################

+

+namespace

+{

+//retrieve raw target data of symlink or junction

+Zstring getSymlinkRawTargetString_impl(const Zstring& linkPath) //throw FileError

+{

+    using namespace zen;

+    const size_t BUFFER_SIZE = 10000;

+    std::vector<char> buffer(BUFFER_SIZE);

+

+    const ssize_t bytesWritten = ::readlink(linkPath.c_str(), &buffer[0], BUFFER_SIZE);

+    if (bytesWritten < 0)

+        THROW_LAST_FILE_ERROR(replaceCpy(_("Cannot resolve symbolic link %x."), L"%x", fmtPath(linkPath)), L"readlink");

+    if (bytesWritten >= static_cast<ssize_t>(BUFFER_SIZE)) //detect truncation, not an error for readlink!

+        throw FileError(replaceCpy(_("Cannot resolve symbolic link %x."), L"%x", fmtPath(linkPath)), L"readlink: buffer truncated.");

+

+    return Zstring(&buffer[0], bytesWritten); //readlink does not append 0-termination!

+}

+

+

+Zstring getResolvedSymlinkPath_impl(const Zstring& linkPath) //throw FileError

+{

+    using namespace zen;

+    char* targetPath = ::realpath(linkPath.c_str(), nullptr);

+    if (!targetPath)

+        THROW_LAST_FILE_ERROR(replaceCpy(_("Cannot determine final path for %x."), L"%x", fmtPath(linkPath)), L"realpath");

+    ZEN_ON_SCOPE_EXIT(::free(targetPath));

+    return targetPath;

+}

+}

+

+

+namespace zen

+{

+inline

+Zstring getSymlinkTargetRaw(const Zstring& linkPath) { return getSymlinkRawTargetString_impl(linkPath); }

+

+inline

+Zstring getResolvedSymlinkPath(const Zstring& linkPath) { return getResolvedSymlinkPath_impl(linkPath); }

+

+}

+

+#endif //SYMLINK_TARGET_H_801783470198357483